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Register Number SATHYABAMA UNIVERSITY (Established under section 3 of UGC Act,1956) Course & Branch :B.Tech – CHEM Max. Marks:80 Title of the Paper :Chemical Engineering Thermodynamics-I Sub. Code :SCHX1002 (2010-11) Time : 3 Hours Date :01/11/2012 Session :FN _______________________________________________________________________________________________________________________________ 1. PART - A Answer ALL the Questions Differentiate Work and Heat. 2. Define irreversible process. 3. What are the limitations of first law of thermodynamics? 4. State Kelvin-Planck statement. 5. What is an equation of state? 6. Define Acentric factor. 7. Show that for an ideal gas Cp-Cv = R from basic principles. 8. Define Joule Thomson Coefficient. 9. Why the inter cooling is necessary in a multi stage compressor? 10. What is compressibility ratio? (10 x 2 = 20) PART – B Answer ALL the Questions (5 x 12 = 60) 11. List out difference between Point function and Path function with examples. (or) 12. Define reversible and irreversible process with examples. 13. Develop the first law of thermodynamics for a steady state flow process. (or) 14. (a) Air at 1 bar and 25°C enters a compressor at low velocity discharges at 3 bar and enters a nozzle in which I expands to final velocity of 600 m/s at the initial condition of pressure and temperature. If work of compression is 240 kJ/kg of air, how much heat must be removed during compression? (b) Oil at 500 K is to be cooled at rate of 5000 kg/hr in an exchanger using cold water available at 295 K. Temperature approach of 10 K is to be maintained at both ends of the exchanger. Specific heat of oil and water is 3.2 and 4.2 kJ/kg K respectively. Determine total entropy change in the process. 15. Prove that the Vander Waal’s constants 27 R 2TC 2 a 64 PC and b RTC 8PC from fundamental principle. (or) 16. Determine molar volume of n-butane at 510 K and 25 barby each of the following (a) Ideal gas equation (2) (b) The generalized compressibility factor correlation (5) (c) The generalized Virial –coefficient correlation (5) Data: PC = 37.96 bar, TC = 425.1 K, at Pr = 0.659 and Tr = 1.2, Z0=0.865, Z1=0.038 and ω =0.2 17. Derive the following 2TV (a) C P CV (b) C P CV R (10) K for an ideal gas (or) 18. Show that (a) dH C P dT (1 T )VdP (2) (b) dU CV dT ( T 1)dV k 19. Show that in multi stage compressor operation, the condition for minimum work is P P P , when the work in all stages is the same, provided that the gas is cooled to the initial temperature each stage. Where P2 is intermediate preesure. (or) 20. A two stage air compressor with ideal intercooler compresses 5 m3/min of free air from 1 bar to 16 bar pressure. The clearance volume in LP cylinder is 4% of its stroke volume. Mechanical efficiency of compression is 80%. Assume compression and expansion follows the law PV1.3= constant. Calculate (a) Work for the compressor (b) Clearance volumetric efficiency in LP cylinder Actual works increase if the air compressed in single stage compressor with same pressure. 2 1 3